1. Field of the Invention
The present invention relates to a door checker interposed between a door support and a door supported on the door support to control the torque for opening and closing the door and to retain the door in a position with a predetermined opening degree, and particularly to an improvement in a structure for pivotally supporting a check plate of a door checker, in which the check plate is turnably supported on a bracket mounted to a door support without looseness.
2. Description of the Related Art
There is a conventional check plate supporting structure, wherein in order to ensure that the check plate is turnably supported on the bracket mounted to the door support without looseness, a bush made of a synthetic resin is fitted into a support bore provided in the check plate; a tapered shaft portion of a pivot secured to the bracket is relatively turnably fitted into a tapered bearing bore in the bush; and a resilient flange adapted to repulse the bush axially to eliminate the looseness between the bush and the pivot is connected to the bush, as disclosed in, for example, Japanese Patent Application Laid-open No.10-18670.
In the conventional check plate supporting structure, a special expensive bush is required, so that it is difficult to reduce the cost.
One example of a simple technique for eliminating the looseness between the pivot secured to the bracket and the bearing bore defined in the check plate is to press-fit the pivot into the bearing bore for relative rotation. With such a press-fitting technique, however, the turning torque of the check plate relative to the bracket is too large, thereby making difficult the manual mounting of the door checker between the door support and the door.
Accordingly, it is an object of the present invention to provide a structure for pivotally supporting a check plate of a door checker, wherein the looseness between the pivot secured to the bracket and the bearing bore defined in the check plate can be eliminated without use of a conventional special bush and without excessive increase in turning torque of the check plate relative to the bracket, thereby preventing generation of an abnormal sound during opening and closing of the door.
To achieve the above object, according to a first feature of the present invention, there is provided a structure for pivotally supporting a check plate of a door checker interposed between a door support and a door supported on the door support, the check plate being turnably supported on a bracket mounted to the door support, wherein a pivot secured to the bracket is relatively turnably press-fitted into a polygonal bearing bore defined in the check plate, and large numbers of pressure-contact portions and gaps are alternately arranged in circumferential directions thereof between an inner peripheral surface of the bearing bore and an outer peripheral surface of the pivot.
The door support corresponds to a body B of an automobile in an embodiment of the present invention, which will be described hereinafter.
With the first feature, the press-fitting of the pivot in the bearing bore ensures that the looseness between the pivot and the bearing bore can be eliminated to prevent an abnormal sound during opening and closing of a door. Moreover, the large numbers of pressure-contact portions and gaps are alternately arranged in the circumferential directions thereof between the inner peripheral surface of the bearing bore and the outer peripheral surface of the pivot, so that when the pressure-contact portions receive a compression load, the gaps adjoining opposite sides of each of the pressure-contact portions permit the resilient deformation of such pressure-contact portions, thereby effectively absorbing the shock of the load. This can contribute to an enhancement in durability of each of the bearing bore, the pivot and the bracket.
Further, it is possible to set the turning torque of the check plate at a relatively small value, while forming by the provision of the gaps the good pressure-contact portions in virtue of a relatively small load for press-fitting the pivot into the bearing bore, and to facilitate manual mounting of the door checker.
Yet further, a special bush is not required and the structure is extremely simple, which can greatly contribute to a reduction in cost.
According to a second feature of the present invention, in addition to the first feature, at least a bearing portion of the check plate, which defines the bearing bore, is made of a synthetic resin.
With the second feature, the bearing portion is made of the synthetic resin, and hence the resilient deformation of the pressure-contact portions occurs easily to effectively achieve both of a reduction in turning torque of the check plate and the elimination of the looseness from around the pivot.
According to a third feature of the present invention, in addition to the second feature, the check plate comprises a plate body made of a metal, and a cover member made of a synthetic resin and mold-coupled to the plate body to cover the plate body, and the bearing portion in close contact with an inner peripheral surface of a through-bore provided in the plate body is integrally connected to the cover member.
With the third feature, the bearing portion made of the synthetic resin can be reinforced by the plate body leading to an enhancement in durability of the bearing portion, and the structure can be simplified by forming the bearing portion integrally with the cover member.